WIP: filter: skip protocol=1 in AT-capable ttyACM filter

This change reduces the scope of the AT-capable ttyACM filter to devices that expose ports with protocols 2 to 6, we will from now on ignore those that claim support for protocol=1.

This is done because Arduino core wrongly claimed for AT protocol support (with protocol=1) in the ttyACMs exposed, and we're just trying to avoid probing all those devices. Even if the interface settings are updated in Arduino core, there are still lots of devices out there that would have the problem, so we'll try to limit the issue in our side.

#140 (closed) #127 (closed) https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=930264